Refractory material and process of making same



Miacas.

ROBERT W. HULL, F HINGHAM, MASSACHUSETTS,

OFICE.

REFRACTORY MATERIAL AND PROCESS OF MAKING SAME.

No Drawing.

To all whomit may concern.

Be it known that I, ROBERT W. HULL, a citizen of the United States of America, and a resident of Hingham, in the county of Plymouth and State of Massachusetts, have invented certain new and useful Improveu nents in Refractory Materials and Processes of Making Same, of which the following is a specification.

This invention relates to refractory material to be used as a lining for surfaces sub jected to intense heat and it has for its object the production of a material of this character composed of the tailings of a concentrating mill in which disseminated chrome ore has been treated.

The invention consists in taking the Waste material left in concentrating disseminated chrome ore and grinding and mixing the same and then uniting the mixture by a suitable binding material.

The invention further consists in subject in said mixture to pressure and forming bricks of the compressed material.

' For the purpose of describing the inven tion one preferred form is described, this form having been found to give satisfactory and reliable results, although it is to be understood that the various elements of the combination can be variously combined, and the invention is not limited to the precise combination of elements as herein described except as required by the scope of the ap pended claims.

When disseminated chrome ore has been concentrated in a suitable mill, the tailings or waste material therefrom has heretofore had no commercial value.

It has been found, however, that these tailings contain about five per cent chromite, combined with quantities of silica, serpentine, olivin, magnesite, and alumina, and these elements when united by a suitable binder make an excellent refractory material particularly adapted to be used for linings of furnaces and other walls subjected to an intense heat.

The tailings or waste material from the concentrators are ground into pulverized form, thoroughly mixed together, and then the entire mass has a binding material mixed therewith.

Portions thereof are then subjected to pressure and formed into bricks or briquettes of such shape and size as to make Specification of Letters Patent.

Application filed April 9,

Patented June 6, 1922.

1921. Serial No. 459,999.

them available in the construction of furnace walls.

These bricks or briquettes are then baked in any usual manner and are ready for the market.

Chromite has been used heretofore in the manufacture of refractory material but in very large proportions relatively to the other elements used in said material.

In the present invention the proportion of chromite used is very small and yet when combined with larger proportions of such elements as silica, serpentine, olivin, magnesite and alumina, arefractory material is produced capable of withstanding the most intense heat.

The chromite, viz: iron oxid and chromic oxid, remaining in the tailings from the concentr'a-tor form only about five per cent of the ingredients usedin the manufacture of the refractory material but this proportion has been found quite sufficient to pro duce a most satisfactory material when combined with such ingredients as silica, serpentine, olivin, magnesite and alumina.

One reason why chromite is not more generally used in the manufacture of refractory materials is because it has'so much greater value in other industrial arts as to make its use prohibitive.

In the present invention, it has been found possible to manufacture the refractory material with that portion of chromite which is useless in other industrial arts and which would be wasted unless utilized in some such manner as is herein described.

In carrying out the manufacture of the invent-ion, the waste material from the concentrator containing chromite, silica, alumina, serpentine, olivin, and magnesite, is pulverized and thoroughly mixed and then a suitable binding material is added thereto.

This mixture is then. formed into desired shapes, under pressure, and baked.

The preferred mixture consists of about five parts chromite and ninety-five parts of silica, alumina, serpentine, olivin, magnesite and binding material.

The binding material used may be pitch, tar, or any other substance suitable for such use and the quantities of silica, alumina, serpent-inc, olivin and magnesite may be used in any desired proportions.

During-the baking of the mixed ingredients, the binding material is so acted upon as to leave a residue of carbon which thoroughly unites the other ingredients and effectually prevents their separation.

hen the ingredients, after mixture, are formed into bricks or briquettes and then baked. the chromite so unites with the other ingredients as to form a hardened exterior surface adapted to resist the most intense heat.

\Vhile for the best results it is preferred to use alli the other ingredients combined with the chromite. it is obvious that good results may be obtained with one or more of these ingredients omitted.

The finished article will resist the highesttemperature.

It is believed that the operation and many advantages of the invention will be under stood readily by reference to the description and to the claims to be hereinafter given.

Having thus described my invention, I claim:

1. A refractory material for surfaces subjected to intense heat comprising waste material left after concentrating disseminatedchrome ore containing a mixture of silica, serpentine and olivin and united by a binder.

2. A refractory material for surfaces subjected to intense heat comprising a mixture of silica, serpentine, olivin, magnesite. and alumina forming about ninety-five per cent of the compound and having mixed therewith and bonded thereto five per cent of chromite.

3. A refractory material for surfaces subjected to intense heat comprising a mixture of silica, serpentine,.olivin, and magnesite forming about ninety-five per cent of the compound and having mixed therewith and bonded thereto five per cent of chromite.

'4. A refractory material for surfaces subjected to intense heat comprising a mixture of silica, serpentine and olivin forming about ninety-five per cent of the compound and having mixed therewith and bonded thereto five per cent of chromite.

5. The process of making refractory material which consists in taking waste material from concentrators containing chromite. magnesite, silica, olivin, serpentine, and alumina; grinding and mixing the same; and then adding a binding material thereto.

6. The process of making refractory material which consists in taking waste material from concentrators containing chromite, magnesite. silica. olivin. serpentine, and alumina; grinding and mixing the same; adding a binding material thereto: subjecting the material to pressure to form it into a' desired shape; and then baking the same.

7. The process of making refractory material which consists in mixing about five per cent of chromite with a mixture containing about ninety-five per cent of ingredients of a crystalline nature: grinding thesame; and adding a binding material thereto.

Signed by me at 294 Washington St. Boston, Mass, this 7th day of April. 1921.

ROBERT V. HULL.

\Vitnesses lVAurnR E. LOMBARD, NATHAN C. LOMBARD. 

